Cons — App store has fewer and less feature-full apps than competing phone OSes. Not all older phone models are upgradeable.

Bottom Line — Windows Phone may be the neglected sibling among smartphone operating systems, but it brings some unique advantages nevertheless.

Microsoft’s mobile operating system has struggled in recent years. Android and iOS basically own the market. But the leading desktop OS vendor isn’t giving in on the quest to disrupt the duopoly that currently dominates the smartphone landscape. A big part of its strategy ties in with its still-dominant position on the desktop. Though Windows 10 Mobile is not identical to Windows 10 on the desktop, it shares a great many features and capabilitieswith its big brother, and ties in tightly with other Microsoft services such as Office 365, Skype, OneDrive, and Xbox One. The OS also boasts standout capabilities like the Cortana intelligent voice assistant, Continuum, which lets you use your phone as a full-size PC, and Windows Hello, which lets you log in with your face. Can all this cool tech spur wider use of the third phone OS? Only time will tell.